The flaskless molding machine that uses a matching plate is known, wherein so as to reuse a pattern plate, the matching plate having a plate-like member is manufactured by putting together the back surface of the pattern-plate having a pattern only on one side and specifically used for an upper molding flask and the back surface of the pattern plate having a pattern only on one side and specifically used for a lower molding flask (See, for example, Patent Document 1).
The flaskless molding machine of Patent Document 1 has two molding flasks that have a matching plate sandwiched between them, the two molding flasks being placed in a way such that each one of the opening ends of each molding flask is opposed to each other and each of the other opening ends of each molding flask is engaged with a squeezing plate (board), whereby a pair of molding spaces is formed, each space being a space to produce a mold, into which spaces the molding sand is filled by air through the openings for sand-feed. Each of the openings is disposed on a wall of each of the two molding flasks that form the pair of molding spaces and that are placed in positions opposed to each other, as described above. The flaskless molding machine thus constituted is able to mold two molds by squeezing the molding sand with the squeezing plates (boards), wherein such flaskless molding machine comprises a driving means that moves at least one of the molding flasks, depending on the thickness of the matching plate, and a driving means that moves at least one of the hoppers or hopper-nozzles, while it moves the positions of the openings for sand-feed disposed on the walls of molding flasks, so that the positions of the hoppers or hopper-nozzles matches the those of the openings for sand-feed.
However, the flaskless molding machine of Patent Document 1 must additionally include large-sized components, such as a cylinder, a member for positioning, parts for the driving means, etc., that move a tank that supplies the sand. Also, as the flaskless molding machine needs two tanks, it will increases the cost for the tanks and their required attachments, compared with a flaskless molding machine that uses only one tank. Further, if a driving means is added, it disadvantageously makes the structure of flaskless molding machine complex.